Here's how to tell a psychopath from a sociopath

The terms psychopath and sociopath are often used
interchangeably, but they aren't quite the same thing.

So what's the difference, you ask?

To find out, we asked James Fallon, a neuroscientist at the
University of California at Irvine School of Medicine who
specializes in studying psychopaths (and also
happens to be one himself).

While neither term appears in the Diagnostic
and Statistical Manual of Mental Disorders, the medical
handbook used by psychiatrists, psychopaths can be divided into
two categories, according to Fallon. The first category includes
what are known as primary psychopaths. The second includes
what are known as secondary psychopaths, or sociopaths.

Here's what sets the two apart:

(Note: These definitions are meant to be informative only, not to
be used as a diagnostic tool.)

Samantha Lee/Business Insider

But that's not all. According to Fallon, both psychopaths and
sociopaths can be further broken down into two subtypes, based on
their demeanor: